Answer:
(a) 913.874 Years.
(b) 8 minutes.
(c) 2.56177 Seconds.
Explanation:
(a) Following Equation relates Distance to Velocity and time.
[tex]$S = Vt$[/tex] (S is for Distance,
in it we have.
S = [tex]8.64*10^{18}m[/tex], V = 299792458m/s (Velocity of Light).
t = ?
Rearranging and solving for time gives us. t = [tex]2.881993788*10^{18}seconds.[/tex]
which when converted to years , we have t = 913.874years, that is how long it will take for us to notice that the star has been burned out.
(b) it take 8 minutes for sun light to reach earth, how.? because distance from earth to sun is 150.46 million Km. doing same calculations as in (a) gives us 8 minutes.
(c) Distance to moon and back is twice as much, because obviously it is round trip, so S = 2 x 3.84x10^5Km.
using same logic as in (a) and (b) we get t = 2.56177 seconds. that is how long light takes to reach moon and come back.
